Crankless motor compressor



April 6, 1937. R. WITKIEWICZ ET AL 2,076,253

CRANKLESS MOTOR COMPRESSOR Filed March 16, 1933 Patented Apr. 6, 1931UNITED STATES PATENT OFFICE".

2,076,258 CRANKLESS Moron comrnnsson Roman Witkiewicz and Adam Wichiski,Lwow, Poland Application March 16, 1933, Serial No. 661,194 In PolandMarch 23, 1932 1 Claim. (Cl. 230-56) Applications have been filed inPoland, on March 23, 1932; in Germany, Austria, and Switzerland onDecember 12, 1932; in the Free City Danzig on December 14, 1932; inCzechoslovakia on De 5 cember 16, 1932; in Sweden on December 20, 1932;

o compressors, and more particularly to a method in Italy, Hungary,Rumania, and France on December 22, 1932; in Belgium on January 6, 1933,and in Denmark on January 5, 1933.

a The present invention relates to crankless motor The hitherto knownconstructional forms of crankless motor compressors possess thedisadvantage that the magnitude of stroke of the compressor parts cannotbe fully utilized inasmuch as only a part of the air contained in thesaid compressor parts can be usefully discharged. The rest of theexpanding air has to perform the work necessary for the production ofthe compression in the motor part of the motor compressor. This resultsin a considerable diminution of the compression pressure dependent uponthe load of the compressors. As a result of this difiiculties are causedin consequence of .the necessity for automatic alteration of the pointofinjection of full independence on the load and alsoin consequence of thelow stability of the automatic regulation process, which may exhibititself by causing un'ceasing disturbances during the pas-'- sages fromone state of equilibrium to anotherrone.

It is one object of the present invention to remove this disadvantage bythe employment of the structure hereinafter described for the attainment of a uniform or approximately uniform compression pressure inthe motor part of a crankless motor compressor. A particularly novelfeature of theinvention resides in the fact that an invariablecompression pressure is obtained by the aid of the work of expansion ofthe gases which are not discharged from the compressor, this work being,however, utilized in combination with the work of expansion of air in aseparate air buffer chamber or chambers. The latterv is intended toeifect an accumulation of energy during the compression -periodin thecompressor parts to'such an extent that thgsum of the energy imparted tothe piston by the air bufi'er chambers and by thev gas expanding in thecompressor during. .the movement of the piston to-- wards the motor partof the-motor compressor is of constant or substantially constantmagnitude independently of the, load at any given time. At the same timethe losses of air arising in the buiier chambers in consequence of lackof air tightness are compensated for by arranging that air is taken upfrom the atmosphere or from a compressed air container by the opening ofports in the cylinder by the faces of the piston during the beginning ofthe movement of the latter. A compensation of the losses of air arisingin the bufier chambers may also be effected by means of an automaticsuction valve arranged in the said chamber, for example on the coverthereof.

A crankless motor compressor constructed for carrying out the aforesaidmethod according to the invention possesses the further advantage thatthe air sucked in by the compressor is not ,throttled, inasmuch as adiminution of the quantity. of air discharged is obtained by diminishingthe quantity of fuel injected with the result that the stroke of thepisggn towards the compression space of the compres r automaticallydiminishes.

A preferred constructional form of a two-stroke cycle motor compressoradapted for carrying out the method according to the invention isillustrated by way of example on the accompanying drawing, in which:

Fig. 1 is a vertical longitudinal motor compressor, and

Fig. 2 is a plan thereof partly section.

Referring to the drawing:

The motor compressor is provided with a cylinder I having an internalchamber 2 in which a combustion engine cycle, for example according tothe Diesel system, takes place. The cylinder L is provided with ports 3serving for the exhaust and ports 4 serving for the scavenging of theinner chamber 2 of the cylinder, the air necessary for scavenging beingderived froma container 5. At the ends of the motor compressor,cylinders Band I are provided having chambers 8 and 9 in which thecompressor operations take place. The cylinders 6 and l are providedwith enlarged section of the in horizontal portions in which bufierpistons 12 and I3 reciprocate, which latter form an integral unit withthe outer compressor pistons and the inner motor pistons. The pistons l2and I3 are connected with one another by means .of a linkage comprisinglink members l4 and I and swinging members l6, whereby the synchronismof the oppositely directed movements of the two pistons is ensured. V

Ports l1 and It provided in the cylinders 6, I serve for the suction ofair into the scavenging pump, which is constituted by the annularchamber l9 located around the chamber 2 of the middle cylinder betweenthe' pistons 82 and H3. The ports I! and I8 also serve for thecompensation of the losses of air arising in the buffer chambers l0 andII in consequence of the unavoidable lack of complete air tightness.

The valves 20 and 25 serve for the admission of fresh air into the twocompressors and the valves 22 and 23 form the pressure valves of thecompressors. The ports 25 together with the conduits 21 and 28 serve forthe completion of the charge of the compressor from the scavenging pumpchamber E9.

The new process elucidated by way of example with reference to the modeof operation of the motor compressor described is based on the following principle. During the movement of the pistons i2 and i3 inwardsfrom the outer position illustrated, the air which has remained in v thecompressor chambers 8, 9 is expanded and fresh air is then sucked in. Atthe same time the air contained in the buffer chambers l0 and II alsoexpands, the sum of the two amounts of work simultaneously executedbeing converted into the kinetic energy of the pistons l2 and I 3. Thesaid kinetic energy is converted in the further course of the operationsinto the work necessary for compressing air in the motor chamber 2 andalso in the chamber 19.

Shortly before reaching the inner dead centre the part 24 of the pistonI uncovers the ports 4 establishing communication with the pump, wherebythe container 5 is charged with the air intended for scavenging. Thebuffer pistons l2 and I3 uncover the ports I! and I8 whereby air issupplied to the buffer chambers to compensate for the losses throughlack of air tightness therein.

Immediately before the inner dead centre position of the pistons i2 andI3 is reached fuel is injected by means of the fuel injection valve 25into the chamber 2. After injection of the fuel the combustion takesplace in the said chamber, the pistons alter their direction of movementaudzthe combustion gases expand in the chamber At the moment when theports 3 are uncovered by the inner pistonsthe combustion gases escapeand the piston l3 uncovers the scavenging ports 4 after the attainmentof atmospheric pressure in the cylinder I. The scavenging air then flowsfrom the container 5 into the cylinder 2 and forces the exhaust gasesout, these latter escaping through the ports 3.

During this return stroke the air in the scavenging pump chamber l9expands, and at the moment when the ports I! and I8 are uncovered thescavenging pump draws in the quantity of air which is necessary forcharging the container 5 later on. At the same time the air in thebuffer chambers l0 and II is compressed, this operation commencingimmediately after the ports I! and 18 have been covered by the pistonsl2 and I3. At this time after the working pressure has been attained airis forced out through the compression valves 22 and 23.

At the end of the suction stroke the compressor pistons uncover theports'26 communicating by additional charging with the container '5 forthe scavenging air. In this case, however, the compressor would becharged to a somewhat lower pressure than that of the scavenging air.

During the movement of the pistons whereby the combustion gases expandin the motor, the kinetic energy of the pistons I2 and I3 is greater,the greater the quantity of injected fuel. In consequence of this thepiston stroke and the amount of air delivered from the compressionchamber of the compressor is likewise greater, the greater the quantityofinjected fuel. The quantity of energy given up by the expanding gasesin the compressor will therefore in this case become smaller andsmaller, but at the same time the quantity of energy yielded up by thebuffer chamber to the piston must increase in consequence of theincrease of stroke and the consequent increase of the pressure in thebuffer chamber. It is not difiicult to arrange that the size of thebufier chamber in proportion to the dimensions of the compressor is suchthat the sum of the quantities of energy given up by the compressor andthe buffer to the piston shall be invariable or only slightly variablewith the load. This principle therefore results in an approximatelyuniform final compression pressure of the fuel mixture or the air in thecombustion chamber of the motor 2.

If the compensation of the air or gas losses resulting from lack of airtightness in the buffer is effected by means of air at a lower pressurethan .8 of an atmosphere above atmospheric pressure (air at atmosphericpressure or at the pressure of the scavenging pump) then the realizationof the principle of approximately uniform compression pressure in themotor is only possible in the case when the operative buffer area isgreater than the cross sectional area of the motor cylinder. If, on theother hand, pressures of more than .8 of an atmosphere above atmosphericpressure are employed, then the operative buffer area may be smallerthan the cross sectional area of the motor cylinder. However, in view ofthe danger of explosion of lubricants and also in view of the heatlosses in the buffer, the ratio 01 the final compression pressure to theinitial pressure must not be greater than 10 at the highest possibleload.

From the above it follows that the characteristic features of a motorcompressor operating according to the invention reside in the facts that(a) the pressure ratio in the buffer is lower than 10, and (b) theoperative buffer area is greater than the cross sectional area of themotor cylinder, if the initial pressure in the buffer is less than .8 ofan atmosphere above atmospheric pressure.

The crankless motor compressor described does not require any regulatingapparatus for adapting the motor output to the compressor output. Theadjustment of the quantity of fuel according to the load may beautomatically effected dependently upon the pressure above atmosphericpressure in the container for the air which is delivered. 4

The fact that the admitted air is not throttled at variable load doesnot cause any additional losses.

means of conduits 21 and 28 with the scavenging w claim;

pump chamber l9, with the result that the compressors are additionallycharged from the said scavenging pump. In this latter the pressure issomewhat higher dln'ing the additional charging than that of thescavenging air. It would also be possible to connect the ports 26 forthe In a crankless motor compressor comprising a motor cylinder, twobuffer cylinders mounted coaxially with said motor cylinder one at eachside thereof, two compressor cylinders mounted coaxially with said motorcylinder one at each side thereof, and two multiple direct-actingfree-flying the pistons is larger than the active surface of the partsacting as motor pistons, whereby a substantially constant final pressureof the compression in the motor, independently of the load,

is attained.

ROMAN WITKIEWICZ.

ADAM wIcIfisKI.

